WebSerial allows your browser to access serial devices, which can be used to flash microcontrollers [1] [2] [3], access serial terminals of those microcontrollers [3] and much more. It's already supported in chromium-based browsers, but Mozilla and WebKit are currently skeptical due to possible fingerprinting and device security concerns.
I think that the fingerprinting problem can be solved by disabling it by default (or by Orion's other anti-fingerprinting methods), and that the benefits far outweigh possible security concerns, as there's yet to be any example of using WebSerial for malicious purposes, and a ton of actually useful web apps using it.
Adding it to Orion would make it the first non-chromium browser to support it, too.
